Page 3369 of 3833

TROUBLE DIAGNOSIS
ATC-93
C
D
E
F
G
H
I
K
L
MA
B
AT C
High-pressure Side is Too Low and Low-pressure Side is Too High.
Both High- and Low-pressure Sides are Too Low.
Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too low and
low-pressure side is too high.High and low-pressure sides
become equal soon after com-
pressor operation stops.Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packingsReplace compressor.
No temperature difference
between high and low-pres-
sure sidesCompressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings.Replace compressor.
AC356A
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too low.
●There is a big temperature
difference between receiver
drier outlet and inlet. Outlet
temperature is extremely
low.
●Liquid tank inlet and expan-
sion valve are frosted.Liquid tank inside is slightly
clogged.
●Replace liquid tank.
●Check lubricant for contami-
nation.
●Temperature of expansion
valve inlet is extremely low
as compared with areas
near liquid tank.
●Expansion valve inlet may
be frosted.
●Temperature difference
occurs somewhere in high-
pressure sideHigh-pressure pipe located
between receiver drier and
expansion valve is clogged.
●Check and repair malfunc-
tioning parts.
●Check lubricant for contami-
nation.
Expansion valve and liquid
tank are warm or only cool
when touched.Low refrigerant charge
↓
Leaking fittings or componentsCheck refrigerant for leaks.
Refer to ATC-146, "
Checking
for Refrigerant Leaks" .
There is a big temperature dif-
ference between expansion
valve inlet and outlet while the
valve itself is frosted.Expansion valve closes a little
compared with the specifica-
tion.
↓
1. Improper expansion valve
adjustment
2. Malfunctioning expansion
valve
3. Outlet and inlet may be
clogged.
●Remove foreign particles by
using compressed air.
●Check lubricant for contami-
nation.
An area of the low-pressure
pipe is colder than areas near
the evaporator outlet.Low-pressure pipe is clogged
or crushed.
●Check and repair malfunc-
tioning parts.
●Check lubricant for contami-
nation.
Air flow volume is not enough
or is too low.Evaporator is frozen.
●Check intake sensor circuit.
Refer to AT C - 1 0 8 , "
Intake
Sensor Circuit"
●Replace compressor.
AC353A
Page 3370 of 3833

ATC-94
TROUBLE DIAGNOSIS
Low-pressure Side Sometimes Becomes Negative.
Low-pressure Side Becomes Negative.
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes
becomes negative.
●Air conditioning system
does not function and does
not cyclically cool the com-
partment air.
●The system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted.Refrigerant does not dis-
charge cyclically.
↓
Moisture is frozen at expan-
sion valve outlet and inlet.
↓
Water is mixed with refriger-
ant.
●Drain water from refrigerant
or replace refrigerant.
●Replace liquid tank.
AC354A
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side becomes nega-
tive.
Liquid tank or front/rear side of
expansion valve's pipe is
frosted or dewed.High-pressure side is closed
and refrigerant does not flow.
↓
Expansion valve or liquid tank
is frosted.Leave the system at rest until
no frost is present. Start it
again to check whether or not
the malfunciton is caused by
water or foreign particles.
●If water is the cause, initially
cooling is okay. Then the
water freezes causing a
blockage. Drain water from
refrigerant or replace refrig-
erant.
●If due to foreign particles,
remove expansion valve
and remove the particles
with dry and compressed air
(not shop air).
●If either of the above meth-
ods cannot correct the mal-
function, replace expansion
valve.
●Replace liquid tank.
●Check lubricant for contami-
nation.
AC362A
Page 3371 of 3833
TROUBLE DIAGNOSIS
ATC-95
C
D
E
F
G
H
I
K
L
MA
B
AT C
Insufficient HeatingEJS001H7
SYMPTOM: Insufficient heating
INSPECTION FLOW
*1ATC-54, "Operational Check".*2ATC-47, "PROCEDURE", see No. 1. *3AT C - 4 7 , "PROCEDURE", see No. 5.
*4ATC-47, "
PROCEDURE", see No. 7. *5ATC-64, "Air Mix Door Motor Circuit".*6AT C - 4 7 , "PROCEDURE", see No.
14.
*7ATC-59, "
LAN System Circuit".*8ATC-70, "Blower Motor Circuit".*9AT C - 6 4 , "Air Mix Door Motor Circuit".
RJIA0550E
Page 3372 of 3833
ATC-96
TROUBLE DIAGNOSIS
*10 QR25 engine; (WITH EURO-OBD)
EC-153, "
ENGINE COOLANT TEM-
PERATURE SENSOR" .
QR25 engine; (WITHOOUT EUR-
OBD)EC-527, "
ENGINE COOLANT
TEMPERATURE SENSOR" .
QR20 engine; (WITH EURO-OBD)
EC-885, "
ENGINE COOLANT TEM-
PERATURE SENSOR" .
QR20 engine; (WITHOUT EURO-
OBD)EC-1213, "
ENGINE COOLANT
TEMPERATURE SENSOR" .
YD engine; EC-1508, "
SYSTEM
DESCRIPTION" .*11 QR engine; CO-9, "
Changing Engine
Coolant" .
YD engine; CO-29, "
Changing
Engine Coolant" .*12 QR engine; CO-9, "
Changing Engine
Coolant" .
YD engine; CO-29, "
Changing
Engine Coolant" .
*13 QR engine; CO-12, "
Checking Radi-
ator Cap" .
YD engine; CO-33, "
Checking Radi-
ator Cap" .
Page 3373 of 3833
TROUBLE DIAGNOSIS
ATC-97
C
D
E
F
G
H
I
K
L
MA
B
AT C
NoiseEJS001H8
SYMPTOM: Noise
INSPECTION FLOW
RJIA1596E
Page 3374 of 3833
ATC-98
TROUBLE DIAGNOSIS
Self-diagnosis
EJS001H9
Symptom: Self-diagnosis cannot be performed.
INSPECTION FLOW
*1ATC-135, "Removal and Installation
for Compressor Clutch".*2ATC-138, "
Inspection".*3AT C - 2 4 , "Maintenance of Lubricant
Quantity in Compressor".
*4ATC-54, "
Operational Check".*5QR engine; EM-12, "Checking Drive
Belts" .
YD engine; EM-118, "
Checking Drive
Belts" .
*1ATC-57, "
Power Supply and Ground
Circuit for Auto Amp.".*2AT C - 1 0 0 , "
Ambient Sensor Circuit".*3ATC-102, "In-vehicle Sensor Circuit".
*4ATC-105, "
Sunload Sensor Circuit".*5ATC-108, "Intake Sensor Circuit".*6AT C - 6 4 , "Air Mix Door Motor Circuit".
*7ATC-54, "
Operational Check".*8ATC-33, "SYMPTOM TABLE".*9AT C - 5 4 , "Operational Check".
RJIA1949E
Page 3375 of 3833
TROUBLE DIAGNOSIS
ATC-99
C
D
E
F
G
H
I
K
L
MA
B
AT C
Memory FunctionEJS001HA
Symptom: Memory function does not operate.
INSPECTION FLOW
*1AT C - 5 7 , "Power Supply and Ground
Circuit for Auto Amp.".*2AT C - 5 4 , "
Operational Check".*3AT C - 4 7 , "PROCEDURE".
*4AT C - 4 4 , "
Auto Amp. Terminals and
Reference Value".
RJIA0552E
Page 3376 of 3833

ATC-100
TROUBLE DIAGNOSIS
Ambient Sensor Circuit
EJS001HB
COMPONENT DESCRIPTION
Ambient Sensor
The ambient sensor is attached on the hood lock stay. It detects
ambient temperature and converts it into a resistance value which is
then input into the auto amplifier.
AMBIENT TEMPERATURE INPUT PROCESS
The automatic amplifier includes a processing circuit for the ambient sensor input. However, when the temper-
ature detected by the ambient sensor increases quickly, the processing circuit retards the auto amp. function.
It only allows the auto amp. to recognize an ambient temperature increase of 0.33°C (0.6°F) per 100 seconds.
As an example, consider stopping for a cup of coffee after high speed driving. Although the actual ambient
temperature has not changed, the temperature detected by the ambient sensor will increase. This is because
the heat from the engine compartment can radiate to the front grille area, location of the ambient sensor.
DIAGNOSTIC PROCEDURE
SYMPTOM: Ambient sensor circuit is open or shorted. (21 or -21 is
indicated on auto amp. As a result of conducting Self-diagnosis
STEP 2.)
1. CHECK VOLTAGE BETWEEN AMBIENT SENSOR HARNESS CONNECTOR AND GROUND
Disconnect ambient sensor harness connector.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
RJIA0048E
RHA051GD
Terminals
Voltage (+)
(-)
ConnectorTerminal (Wire
color)
E38 1 (L/OR) Ground Approx. 5V
RJIA1950E